<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./vue.js"></script>
    <style>
        .box{
            width:200px;
            height:200px;
            background: rgb(134, 97, 97);
        }
        
    </style>
</head>
<body>
    <div id="app">
        <div :style="{width:100+200+'px',height:100>200?'300px':'50px',background:'red'}"></div>
        <div :style="obj"></div>
    </div>
    <script>
        let vm = new Vue({
            el:"#app",
            data:{
                obj:{
                    width:'100px',
                    height:'500px',
                    background:'blue'
                }
            }
        })
    </script>
</body>
</html>